Lie on your back. Keeping your torso straight, bend your knees and bring them to one side so they are resting on the floor. Clasp your hands together behind your head. Lift your shoulders off the floor in a crunch motion. Keep your shoulders even as if you are doing a regular crunch. Bring your knees back up to center and down to the other side. Lift your shoulders and crunch again. Repeat, alternating sides.